Borax Mineral Data

General Borax Information

Chemical Formula:

Na2B4O5(OH)4•8(H2O)

Composition:

Molecular Weight = 381.37 gm

Sodium 12.06 % Na 16.25 % Na₂O

Boron 11.34 % B 36.51 % B₂O₃

Hydrogen 5.29 % H 47.24 % H₂O

Oxygen 71.32 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₂(B₄O₅)(OH)₄•8(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1753

Locality:

Link to MinDat.org Location Data.

Name Origin:

From the Arabic buraq, for "white."

Name Pronunciation:

Borax

Synonym:

ICSD 30506

PDF 33-1215

Tincal

Borax Image

Images:

Borax

Comments: Translucent crystal of borax preserved in oil to prevent dehydration to tincalconite.
Location: Searles Lake, San Bernardino County, California, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Borax Crystallography

Axial Ratios:

a:b:c =1.1109:1:1.1873

Cell Dimensions:

a = 11.858, b = 10.674, c = 12.674, Z = 4; beta = 106.583° V = 1,537.46 Den(Calc)= 1.65

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: A2/a

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 4.82(1), 5.68(0.9), 2.56(0.65),

Forms:

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Forms: ( 1 1 1) ( 1 1 2) ( 0 1 0) ( 1 0 0) ( 1 1 0) ( 0 0 1)

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Physical Properties of Borax

Cleavage:

{100} Perfect, {110} Perfect

Color:

Blue, Colorless, Green, Gray, Gray white.

Density:

1.7 - 1.72, Average = 1.71

Diaphaneity:

Translucent to opaque

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Habit:

Tabular - Form dimensions are thin in one direction.

Hardness:

2-2.5 - Gypsum-Finger Nail

Luminescence:

Non-fluorescent.

Luster:

Greasy (Oily)

Streak:

white

Optical Properties of Borax

Gladstone-Dale:

CI meas= -0.003 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.039 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2805,KPDmeas= 0.2707,KC= 0.27
Ncalc = 1.45 - 1.46

Optical Data:

Biaxial (-), a=1.447, b=1.469-1.47, g=1.472, bire=0.0250, 2V(Calc)=32-40, 2V(Meas)=39-40. Dispersion r > v distinct.

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Borax

Electron Density:

Bulk Density (Electron Density)=1.78 gm/cc
note: Specific Gravity of Borax =1.71 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Borax= 0.47 barns/electron
U=PE_Borax x rElectron Density= 0.84 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Borax is Not Radioactive

Borax Classification

Dana Class:

26.04.01.01 (26)Hydrated Borates Containing Hydroxyl or Halogen

(26.04)Dana Type

(26.04.01)Dana Group

26.04.01.01 Borax Na2B4O5(OH)4•8(H2O) A2/a 2/m

Strunz Class:

06.DA.10 06 - BORATES

06.D - Tetraborates

06.DA -Neso-tetraborates

06.DA.10 Borax Na2B4O5(OH)4•8(H2O) A2/a 2/m

Other Borax Information

See Also:

Links to other databases for Borax :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineral and Gemstone Kingdom
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info
17 - WWW-MINCRYST

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Print or Cut-and-Paste your Borax Specimen Label here :

Borax

Na2B4O5(OH)4•8(H2O)
Dana No: 26.04.01.01 Strunz No: 06.DA.10
Locality:

Notes:

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